Many calibration methods calibrate a pair of sensors at a time. For robotic systems with many sensors, they are often time-consuming to use, and can also lead to inaccurate results. In this paper, we combine a number of ideas in the literature to derive a unified framework that jointly calibrates many sensors a large system. Key to our approach are (i) grouping sensors to produce 3D data, thereby providing a unifying formalism that allows us to jointly calibrate all of the groups at the same, (ii) using a variety of geometric constraints to perform the calibration, and (iii) sharing sensors between groups to increase robustness. We show that this gives a simple method that is easily applicable to calibrating large systems. Our experiments show that this method not only reduces calibration error, but also requires less human time.